Shimano Tiagra RD-4601-SS rear derailleur with medium cage for 10-speed shifting systems. Modern Shimano technology for fitness cyclists. The Tiagra groupset is based on the the top Shimano groups, but with its own distinctive identity. 10-speed rear derailleur with pleasant finish, low weight and Wide-Link-design for high stiffness and long durability. Smooth gear changes for carefree cycling.